Benjamin Herrenschmidt wrote:
The intention of the cpu_hotplug_driver_locks to add additional serialization
during cpu hotplug operations. For pseries this is used during DLPAR of cpu
operations so that cpu hotplug actions cannot be initiated whiloe a DLPAR
operation is in flight. For example, during DLPAR add we take the lock while
acquiring the cpu from firmware and updating the device tree with the new
cpu information, after which we hotplug add the cpu to the system.
There is nothing harmless about taking the lock on all platforms, I was just
trying to avoid taking the lock if the additional serialization is not needed.
If so, you could just make the mutex available to all powerpc code, and
rename it, and then we wouldn't need all this jiggery pokery just to
take & release a lock.
I can make the lock available to all powerpc code and not go through the
ppc_md struct, it makes no difference to me personally. Of course this would
make all that fun pokery jiggery go away :)
Yeah, Michael is right, just make it global to powerpc, it should make
things simpler.
Sounds good, I'll get a patch out to do this.
-Nathan
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
